Silvertone 3004 need help!!!!

First topic message reminder :

Hi all,
My name is Frank and I am new to this forum. I have a Silvertone 3004 that I recently acquired, all the capacitors, resistors and electrolytic capacitors have been replaced and checked. Once this was done all I got from the speaker was static, would not pick up any radio stations. The radio from the previous owner had been tinker with and had to be re-wired in some areas and cap & resistors moved around in other places. All this has been correct and is wired and has all cap's and resistors installed correctly, but still no stations just static.

It was suggested that I acquire a signal generator. I have since purchased an Eico 324 signal generator and am in the process of learning how to use it correctly. Here is is a pic of it and what came with it. I have download the instruction manual, but it is greek to me as I am brand new to this field of radio repairs. Not sure which side of the signal generator I need to use or what each control knob does? i.e. AF Mod/Output/RF Coarse etc. Any and all help would be sincerely appreciated.. Thanks in advance.

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Tom, do you think we would be wasting our time if Frank subbed all the tubes for a known good set? I have a set I can send him.

WC

Small voltage changes to the AC input or B+isn't likely to cause any noticeable fading, only likely hood would be a all but failed tube...

Without a variac, a good test would connect it to a dim bulb tester to see if it will play at 85-100v...

WC, Thanks. I checked the tuning capacitors and found no crud in between the fins, so that looks good. Did the voltage test DC on tube 35W4 pin 7 ( voltage reading between 127-128 notice small surge went from 127 to 129 back and forth. Took this a step further not sure if it matters or not in regards to voltage reading. I took the volume control and turned it were it was just about in the off position voltage reading was 129-130, moved volume control to about 12: 00 o'clock position voltage was 115-117, all the way clockwise 127-128, again not sure if this matter. Also touch the center post volume control with solder iron buzz was produced. You also recommended checking  tube 50L6 pin 5, and no voltage, did you mean pin 3? if so 119-121 V.

Cliff, that will really help. Thank you!

Tom, do you or Cliff either one think that there is a possibility that there is a tube with a thermal expansion issue? Frank states that when the radio fades, the tubes stay lit. Could we have an element in one of the tubes that is getting hot, expanding so that it kills the signal? I'm getting a set of tubes ready to go, just in case. I am trying them out in a radio to make sure they do not have issues. I like subbing tubes in cases like this.

WC

I am thinking along these lines, That if it does receive any stations and its not atmospheric then its a heat related issue with components. Either a capacitor, or resistor is opening up or a cold solder joint. So just keep that in mind as we further delve into your radio.
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I do like the systematic approach that is being used here. Because of that I would suggest the following. Either write down each of the steps that you have gone though, and make room for additional notes and observations, or copy this forum by doing the following:

Go to the top of the screen in your browser and do a mouse click on edit, you will then see a small popup screen with choices of cut, copy, paste, select all, Find on this page.....

Select the choice ----> Select all
Then select ----> copy
this will put the discussion into the clipboard.
After you have done this, then open a text editor such as notepad or MSWord.
Do a Paste then do a save as into a favorite folder.
Then you can edit out things you want to.
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The second method (which I prefer) is
when your on the page in the forum you want save, is to do the following:
Again go up to the tools menu and click on the file menu, and click on save as then in the bottom of the page is the file name, and below that select Web Archive single file (*.mht)
Then select the folder you want to store it in and click on the save button.
The great reason for following the second method is that it will also save the graphics which has pictures that you will not lose.

Tom,
On the closest radio statio. Yes it has been a test of patients for sure!!! Now just need to get it when I turn it on I don't have to worry about how long my station is going to stay on, or how long it will take before a station comes in.

Frank

This fading are you talking about at night when stations often come and go or is this a problem on your closest stations available??




BTW congrats on getting it to operate, this one has been a test of patience for sure...


Tom

We need to get that fading under control before we can attempt an alignment. That would be like adjusting the carburetor after the engine has stalled. I emailed you suggestions to try. Let's take this a step at a time. Sorry about the redundant question on the static. I see you answered it. I am getting old and forgetful it seems.

WC

WC, Finally got a station to come in and yes when it faded out and it was clean static.


Frank

WC, My mistake  . When set on the correct setting it was 118-119 V. In my opinion it sounds like clean static. We can do the alignment at any time.


Frank

Frank, pin 5 of the 35W4 will have AC on it. You may have been using your meter set on DC to get that kind of reading. If you truly had -1.5 volts on pin 5, the radio would be graveyard dead. Pin 5 is basically the positive side of the line. Set your meter to AC and take the reading again. We need to do a thorough alignment on your radio. When the station fades, does it sound like lightning crashing in the speaker? Or does it just get "clean" static, like water rushing? There is a BIG difference in the repair of those two conditions. You have the radio working. Please don't cause yourself undue concern by second guessing yourself. When do you want to do the alignment?

WC

Just re-checking my voltage measurements and notice one, that I am not sure if we addressed it or not on the other forum. My 35W4 tube pin #5 per the schematic should have 117 V mind has - 1.5. I assume that can't be good,

WC, I have reads Cliff's post in regards to the signal generator. I have had the radio running on and off and it seems to work fine for a while then the station fades out or becomes really static. I live in the middle of no were and stations are hard to come by. I will double check the stations against my working am radio and see what I come up with. As far as the radio tuning it is broadly and not sensitive at all. I have the alignment data for this radio

You did well, Frank. It feels good to get your first radio going, especially one that was a pain like that one. It ended up being a poor solder joint on the antenna. One in a million. Good job.

On alignment, you need to read Cliff's post on your generator to make sure you are familiar with how it works. And have an isolation cap handy. Questions first. How does the radio tune? Are the stations where they should be? Does the radio tune accurately or does the station persist way past where you think it should not be? What I need to know is does the radio tune accurately or broadly? That will make a difference. Is the radio sensitive? Does it receive all the stations that other sets in your home will? What alignment means is that you are going to make sure the oscillator is tracking properly and that the stations appear the correct place on the dial, and only once on the dial. After you determine these conditions, we can proceed with alignment, confident that we are actually addressing issues, rather than just excercising our signal generator. And then you need to have the alignment instructions for your radio, which I did not print out. If you would like me to, I will be happy to. Let me know what you find.

WC

WC

ALL I believe we have ignition        I went back and check the antenna wires and could not find a break, I went ahead and re-connected to the antenna board and everything seems to be working fine. Again I sincerely thank everyone that was involved in this. Rest assure this is not my last project. I have another one in the works some were I can feel it. I ready to proceed to the alignment stage.





FYI just heard today is National Radio Day!!!!!!

   Frank, Congratulations!!!!

The long wire functioned for the antenna, and your body worked like a capacitor for the AVC line and provided a ground. DO not do that again! You could get seriously buzzed! Now you need to find a new antenna. The sound will appear muddled until you do, since one side of the antenna goes to the AVC circuit. You have an open antenna. Take your ohmmeter, set on the lowest scale, preferably the analong one, with the radio off, and measure between the two wires going to the antenna. A good antenna reads just a few ohms. An open one will read infinity or thereabouts. You need to look closely at the antenna to see where the break is. It has extremely fine wire, so this can be tedious. After you get the antenna issue resolved, you need to check alignment. We will talk you thru that after we get the antenna repaired. Good luck, and let me know how this comes out.

Frank, old buddy, I could not be happier for you. What did I tell you about the feeling the first time you heard that radio talk? YOU ARE NOW AN OFFICIAL RADIOMAN!! Good going, nobody has ever worked harder.

WC

WC, Tried the second test and   !!!! I got sound, music that whole thing. As long as the wire going to the oscillator section of the tuning cap is touched and held and some part of the radio is touched everything works. If I remove my hand from the radio, but still have the tuning cap wire connected the radio works, but is really garbled but as soon as I re-touch the radio it clears up. Thanks everyone!!!!

Frank, another thing to try, maybe simpler. Get a piece of wire about 10 feet long. Length does not have to be exact. Any kind of wire will do. If nothing else an unplugged extension cord will do. Hook that piece of wire to the point on the tuning cap you touched with your screwdriver. See if the radio plays. This chunk of wire should make the radio play if the antenna is open somewhere. It may not play the best, but that is okay. We just need to hear it talk. Good luck.

WC

That is actually quite good news, Frank.  This means that the If transformers are okay.  What do you say, Cliff?  Is Frank not ready for an alignment?  Why is this radio not working if he can get noise thru the entire set?  Could we have a wire broken in the antenna somewhere and just not have a working antenna?  We have GOT to be getting close here, guys.  We are already to the antenna.  There ain't much else.  

Tell ya what, Frank.  Try this.  On the terminal that you touched with your screwdriver, connect your signal generator, at If frequency, thru the isolation capacitor.  See if you hear the generator in the speaker.  If you do, the antenna has got to be wonky somehow.  This is great, Frank.  Good job.  You are getting warmer.

Thanks, Cliff, for the permission to link.  BTW, do we do pictures here like on TRF?  If not, how?  Frank does fantastic pictures, and we may need some.  



Drat it won't let me post a link for seven days.

WC
------------- Added the History link above and here's the link for posting pictures on our forum.
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No, go ahead and link to the other for reference.  

OK! I found the link and for those that have not been following this repair tutorial, you can link to another Forum that the discussion started on. In case your interested.Click Here for reviewing

Sounds like we are headed into full steam mode. 

Cliff,
By the way thanks for all this useful information on the Eico 324 signal generator. Now I have an idea of how I need to operated this piece of test equipment. I also know that the RF connections that came with this Eico 324 are incomplete. I have ratified that problems.

WC, Thanks for the advice. I checked the antenna wire going to the oscillator section of the tuning cap as suggested with the tip of a screwdriver, and BINGO noise were heard in the speaker a cracking sounds. As stated I believe who ever had this before me was using it for more than just a radio as noted on the other forum.

Frank

Cliff, this is the radio Frank was working on at "the other forum." I think you mentioned "a lot of good tutoring going on" in regards to this radio. So that we are all up to speed, Frank has gone thru like 18 pages of different steps, checked every voltage, ran every wire, checked every connection. He has literally been thru this radio from stem to stern, and really should have a working radio by now. There is still a bug we have yet to find. He was to the point he needed a signal generator to continue. We need to see if we can get a modulated signal, at IF frequency, thru the IF transformers as our next step. We can link the progress of this project thus far, if you think that would get everybody up to speed better. The last we worked on this, I advised him to use an isolation capacitor in the hot lead of his generator, since he is working without an isolation transformer. I want him to err on the side of caution. I appreciate your input on signal generators, as that will help him. He has been tinkering with his generator somewhat, but it is now time to get down to business. If you could advise us if you would have a problem with a link from before, it would let us know how best to proceed. Frank is one of those rare individuals who is willing to do whatever he needs to do to learn. I hope we can all help him to get his radio going. My suspicion is that someone has turned down all the screws in the IF cans and has gotten this thing seriously out of alignment. Silver mica disease has been tentatively ruled out. We can still have an issue with the IF cans, however. One thing I did not read us looking at was the antenna. Frank, before we get to the signal generator, please do this. The schematic shows the antenna as a loop. Probably wound on the back of the radio, right? One wire of the antenna should go to the oscillator section of the tuning cap, and one wire should go to the AVC bus. Find the wire that goes to the oscillator section of the tuning cap, with the radio turned on, touch that wire on the oscillator cap with the tip of a screwdriver. Just touch it. What we want to do is to introduce noise into the radio and see if you can hear it in the speaker. If so, we have an antenna problem. If not, we continue with the signal generator. We will need to do an alignment as a last step in either case. Good luck, and let me know what happens. Thanks, Cliff, for letting us work with Frank to get this thing going for him.

WC

Here's what you need to read:

GENERAL DESCRIPTION
The EICO Model 324 RF Signal Generator is intended for general radio or television servicing and for other applications requiring a modulated or unmodulated r-f signal of sine waveform from 175 kc to 420 mc.
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modulated means that the Radio Frequency signal that is generated has not just the carrier signal but the audio signal mixed in it also, to provide an audible tone that you can hear when the signal that is mixed gets separated inside the radio.

The r-f output from the Model 324 may be modulated internally by a 400 cps audio oscillator or may be modulated externally by on audio signal fed into a connector on the front panel.

The internal 400 cps modulating signal is also
available separately at a front-panel connector. Selection of external modulation rearranges the audio oscillator stage as on amplifier operating an the external modulation signal. As a result, up to 30% modulation is possible when the output of the external a-f source is as low as 3.0 volts. Percentage modulation by either an internal or external a-f source, as well as a-f output voltage, is adjustable by a single panel control.
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The Model 324 incorporates both coarse and fine r-f attenuators for smooth,
efficient control of the r-f output signal. The coarse attenuator provides two steps of coarse attenuation of approximately 20 db. each.
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attenuation- means to reduce a signal to a lower level and 20db is an electrical measurement standard used for gain or loss by a known quantity.
The Model 324 employs a Colpitts-type r-f oscillator and a Colpitts-type audio oscillator of proven design for efficient and trouble-free operation.


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FUNCTIONS OF CONTROLS AND TERMINALS
 
SIGNAL SEL. - Turns power off in "OFF" position. in ‘INT. MOD./AF OUT‘
position, modulated r-f output is available at the RF OUT connector and 400 cycle audio signal is available at the AUDIO IN/OUT connectors. in "RF/
EXT. MOD" position, pure or extemally modulated r-f output is available at the RF OUT connector depending on whether or not any external modulating
signal is fed to the AUDIO lN/OUT connectors.
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extemally modulated Note: You could use an audio oscillator to determine the limit of audio frequency response-you could also hook up a CD - Tape - record player and use it as a miniature radio broadcast station.

BAND SEL. - Used to select desired tuning band. Frequencies in lower three bands (from i5Olzc to 3.5 me) as well as the linear reference scale are read in
the upper window. Frequencies in higher tour bands (3.5 mc to 435mc) are read in the lower window. Note that position F is used when tuning frequencies in either band Fi or F2.

TUNING (knob between windows): - Permits adjustment of RF output frequency to exact value. The RF output frequency is the setting directly under the
illuminated hairline on the scale for the band selected with the BAND SEL.

RF OUT - The output cable supplied with the Model 324 should be connected to the RF OUT connector. The amount of output voltage is controlled by the
RF COARSE and RF FINE attenuators.
This is used to insert a signal with a probe into different stages of the radio to see if the signal is in a working section.

RF COARSE - Permits adjustment of the RF output in coarse steps of approximately 2Odb each. This is a primary rather than a secondary adjustment.

RF FINE - Continuous control permits exact adjustment of the RF output voltage. This is a secondary rather than a primary adjustment.

AUDIO IN/OUT - Has a double function. When the SIGNAL SEL. switch is set to “INT. MOD./AF OUT“, a 400 cps audio signal from the internal audio oscillator is fed to this connector. The audio output voltage is adjustable From zero to a maximum depending upon the load by the AF/MOD. OUTPUT control .

When the switch is turned to "RF/EXT. MOD." an external modulating signal up to l5kc may be injected at AF IN/OUT to modulate the rf output taken
from the RF OUT connector.

NOTE: When using external modulation, the AF MOD./OUTPUT control should be turned clockwise in order to prevent short-circuiting the modulating signal to ground. in use, this control may be used as an attenuator to adjust the amount of injected modulating signal. As the Model 324 provides a stage of amplification for the external modulating signal, a signal of only 3.0 volts approximately is required to modulate the r—f oscillator to 30% at 1000 cps (at I mc RF setting).

AF MOD/OUTPUT - Has three functions.
1) Adjusts the percentage of internal
modulation when the SIGNAL SEL. is set at "INT. MOD./AF OUT.

2)Adjusts the amount of audio signal available at the AUDIO IN/OUT connectors
when the SIGNAL SEL. is set at “INT. MOD./AF OUT‘.

3) Adjusts the percentage of external modulation when the SIGNAL SEL. is set at "RF/EXT.MOD." and an external modulating signal is injected at the AUDIO IN/OUT connectors.

Thanks!!!

Riders put out a booklet on the use of signal generators. I'll see if I can post the free PDF file, Well worth reading!

Thanks. Still waiting on some supplies I ordered before I proceed.

First off if you don't know the basic terminology you are already in deep trouble to start with.
So Here's my suggestions for you.
These will help in understanding what your working with.
1. Go online and find a dictionary or glossary on Electronic Terminology.
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2. There are free pdf files on understanding how to use a signal generator.
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3. Find a book or PDF on Basic Radio Trouble shooting and its methods and Tips.
( will be back later with links) as I am so tired I can't concentrate right now-5:30 PM nap over Due.   
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If any one wants to follow-up go Ahead.

Hi all,
My name is Frank and I am new to this forum. I have a Silvertone 3004 that I recently acquired, all the capacitors, resistors and electrolytic capacitors have been replaced and checked. Once this was done all I got from the speaker was static, would not pick up any radio stations. The radio from the previous owner had been tinker with and had to be re-wired in some areas and cap & resistors moved around in other places. All this has been correct and is wired and has all cap's and resistors installed correctly, but still no stations just static.

It was suggested that I acquire a signal generator. I have since purchased an Eico 324 signal generator and am in the process of learning how to use it correctly. Here is is a pic of it and what came with it. I have download the instruction manual, but it is greek to me as I am brand new to this field of radio repairs. Not sure which side of the signal generator I need to use or what each control knob does? i.e. AF Mod/Output/RF Coarse etc. Any and all help would be sincerely appreciated.. Thanks in advance.

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